Antihypertensive and renal effects of tertatolol, a new beta-blocking agent, in hypertensive patients

Tertatolol, a new nonselective β-adrenoceptor blocker, was administered to 11 hypertensive patients in a short-term study. Systolic and diastolic blood pressure and heart rate were significantly decreased when compared to the placebo period: In spite of that glomerular filtration rate and renal plasma flow were unchanged. The administration of metoclopramide (a dopaminergic receptor antagonist) caused a significant reduction of renal plasma flow and a significant rise of renal vascular resistances during placebo, but no change during tertatolol therapy. A possible interference of tertatolol on dopaminergic receptors is discussed as the mechanism reponsible for the unmodified renal plasma flow despite the significant blood pressure lowering with tertatolol.